The invention generally relates to a wireless communication network, and more particularly, relates to an improved home location register (HLR) that provides fraud protection mediation in a wireless communication network.
Wireless communication is one of the fastest growing segments of the telecommunication industry. With the mobility of the wireless devices, such as cellular phones and pagers, a subscriber to a wireless service can make or receive a call or receive a message without being restricted to any particular locations. Because of the convenience provided by wireless devices, they have been widely used by average consumers.
Wireless communications are provided through a wireless communication network, which can be realized, for example, as a Signaling System 7 (SS7) network. The SS7 network uses the EIA/TIA Interim Standard 41 (IS-41) protocol, which is the standard commonly used in North America. A description of the SS7 network and the IS-41 protocol can be found in Signaling System #7, by Travis Russell, and The Mobile Communications Handbook, by Jerry Gibson, which are hereby incorporated by reference.
The SS7 network is used for switching data messages pertaining to connecting telephone calls and for maintaining the signaling network. As shown in FIG. 1, the SS7 network 100 has three different types of nodes or signaling points: Service Switching Point (SSP) 112, Signal Transfer Point (STP) 116, and Service Control Point (SCP) 122.
An SSP 112 is a local exchange in the telephone network. An SSP 112 uses the information provided by the calling party (such as dialed digits) and determines how to connect the call. An STP 116 serves as a router in the SS7 network and switches SS7 messages as received from the various SSPs 112 through the network to their appropriate destinations. An STP 116 receives messages in packet form from an SSP 112. These packets are either related to call connections or database queries for an SCP 122. If the packet is a request from an SSP 112 to connect a call, the message must be forwarded to the destination where the call will be terminated. The destination is determined by the dialed digits. If the message is a database query seeking additional information regarding a person who subscribes a wireless service, i.e., a "subscriber", the destination will be a database. Access to telephone company databases is provided through an SCP 122. These databases are used to store information about subscribers' services, calling card validation, fraud protection, etc.
As shown in FIG. 1, the wireless network is shared by multiple regions 126, such as regions A and B. In each region 126, an SCP 122 is provided. Each region 126 is further divided into a number of registration areas 132, each of which is served by a Mobile Switching Center (MSC) 136. An MSC 136 provides wireless communication services to all properly registered cellular phones 142 in the registration area.
As illustrated in FIG. 1, an SCP 122 contains an authentication center (AC) 146 and a home location registers (HLR) 152. AC 146 authenticates a subscriber's cellular phone through the use of an encrypted number called the A-Key. HLR 152 is used to store information regarding cellular subscribers in the region for which it provides services. HLR 152 also stores information identifying the services allowed for each subscriber. In addition to these, HLR 152 stores the current locations of cellular phones 142 of those subscriber's who initially activated their cellular phones through a wireless service provider in the region the HLR serves. This region is also referred to as the "home area" of those subscribers. Although not shown, a backup HLR is also provided in SCP 122.
A visitor location register (VLR) 156 is also provided in each region 126. VLR 156 is used when a cellular phone 142 is not recognized by a local MSC. VLR 156 stores the current locations for the visiting subscribers.
With the unparalleled growth of wireless communications services has come an equally noteworthy but unfortunate trend. Cellular fraud--the theft of cellular airtime by criminals employing a variety of methods--has become an enormous business challenge for cellular carriers and a nuisance for legitimate cellular subscribers. In the United States alone, industry estimates of lost revenue attributed to unauthorized use of cellular networks range from US$1 million to close to US$3 million per day. Carriers' ability to detect cellular fraud, manage it, and to the extend they can, prevent it has become critical to sustaining both profitability and competitive advantage.
HLR-based fraud protection feature has been implemented by automatically locking cellular phones when they are inactive. This prevents unauthorized use of a subscriber's phone and/or fraudulent access to the network by cloned phones. When a subscriber initially registers with the network, the HLR requires the subscriber to enter a feature code and personal identification number (PIN) before access is granted. The subscriber can then lock the phone again by entering the same feature code and PIN. If an unlocked phone becomes inactive for a predetermined period of time, the HLR automatically invokes the fraud protection feature until the subscriber unlocks the phone with feature code and PIN entries. This feature prevents access to the network by a cloned phone using the valid subscriber's MIN (Mobile ID Number) or ESN (Equipment Serial Number) while the valid subscriber is inactive.
However, in areas where authentication processing operates to authenticate cellular phones, it may not be necessary to operate fraud protection processing which requires a subscriber to enter a PIN to unlock his cellular phone for accessing the network. To provide convenience to subscribers so that they do not have to enter their PINs to use their phones, fraud protection processing should be operated in areas where authentication processing is not available.
Accordingly, fraud protection mediation is needed in different areas that support either authentication processing or fraud protection processing, or both. This will provide great convenience to subscribers in those areas where authentication processing is performed on cellular phones.